TheGreenButton - Windows Media Center Forums

Codec differences is a good point. I forgot that the US is not using H.264 as much as we are.

HD in the UK basically means H.264

All ATSC content in the US is MPEG-2* - content that will normally be handled by a set-top box (whether cable or Satellite) can be any format the set-top box can handle. Satellite content has always required a STB for every screen, so they made the move to h.264 sooner, but Cable companies stuck with cheaper components for longer, and had a lot more of them, so they've been less vigorous about moving to h.264 content

WMC should be able to handle H.264 content, though older Extenders don't (the DMA-2x00 extenders are perfectly capable of playing H.264 content, they just won't do so if the container is .WTV). Is the H.264 content that you are receiving Copy-Protected?

* H.264 support was actually added to the ATSC specification about 6 months before the digital switchover, much too late for a lot of the hardware that was purchased in the run-up to the switchover, and a lot of that hardware is still in use.

As far as I know, the i50/p25 switching in the UK has only been seen to cause stuttering for WMC users. In my case, 7MC is badly affected, but my TV receiver is not. As I understand it, the improved image quality and compression ratio provided by MPEG4/AVC/H.264 over MPEG2, means the decoder has to work much harder to output the data in real time. So it seems likely that a software decoder may be vulnerable to stuttering where a hardware implementation is not.

However, it's also possible that the Microsoft video decoder in MSMPEG2VDEC.dll (which supports H.264 despite it's name) does not handle these frame-rate changes properly. I'm willing to throw hardware at this problem (if I only knew what hardware), but AFAIK, neither the BBC nor Microsoft seem interested in providing support.

I believe a later version of MSMPEG2VDEC.dll ships with Windows 8, so I wondered optimistically if any 8MC users in the UK have seen stuttering on BBC HD terrestrial (FreeView) transmissions?

I think that MC uses MSDTVVDEC.dll for TV.

My Echo extender plays back the file with very little stutter visible.

I meant to try playing the file in VLC last night but forgot, not sure if it shows the same effect?

msdtvvdec.dll is interesting. I can't find a copy on my Win7 system disc.
I thought msmpeg2vdec.dll was the media foundation codec but maybe it's the direct x equivalent?

Just wondering if anyone here has found a proper solution to this problem as it appears that the BBC have started using this new encoder on DVB-S2 broadcasts too.

See http://www.thegreenbutton.tv/forums/vie ... 28&p=54588